Foraging behaviour of Ross seals in King Haakon VII Sea: an opportunity lost?

A proposed study into the ranging and diving behaviour of Ross seals Ommatophoca rossii in an area of high relative abundance in the eastern Weddell Sea, and their diet through direct (stomach contents and scats) and indirect (dive behaviour, jaw activity recordings and stable isotope analyses) means was turned down for the SANAP research period 2012-2014. The aim was to improve knowledge of the way oceanographic conditions affect one of the four true Antarctic species of seal breeding off the Princess Martha Coast, Antarctica in the King Haakon VII Sea with a view to using Ross seals as bioindicators of environmental change under a scenario of ocean warming, progressive disintegration of the West Antarctic ice-sheet and decrease in sea-ice coverage. Designed to build on earlier SANAP seal research in this area of pack-ice in the late 1970’s and early 1990’s, using the new SA Agulhas II as the research platform, it would apply latest technology such as Conductivity, Temperature, Depth (CTD)-Satellite Relay Data Loggers (SRDLs), Mandible Accelerometers (MACs) and stable isotope analyses to characterise Ross seal distribution, diet and physical characteristics of the water column where they forage. Ross seals are ideal candidates as they made long foraging trips north of the pack-ice into pelagic areas of the Southern Ocean for most of the year (in 2001) and returned to the pack-ice only for short periods to breed and moult. The comprehensive analysis and synthesis of biological and physical data perceivably could make an important contribution to determining relationships between hydrographic features, ocean currents, sea floor characteristics, prey dynamics, and the distribution and abundance of marine top predators. A possible way forward in the use of a top predator as an oceanographic profiler to detailing the structure and function of the pack-ice ecosystem likely affected by global warming is presented